Fabrication and properties of rapidly solidified powder-based high-temperature application light-alloy composites

Particulate-reinforced composites based on Al-Fe-Ce and SiC were fabricated by conventional powder metallurgy techniques, namely powder mixing, cold compaction and hot extrusion. Static mechanical properties at ambient temperature and at elevated temperature after prolonged exposure to the test temperature were measured and related to process parameters and the volume fraction of the reinforcement. The addition of SiC particles in considerable volume fractions help to retain the static properties at high temperature, even after prolonged exposure. It was also observed that the mechanical strength increases with decreasing temperature and extrusion ratio. Unavoidable non-uniform distribution of SiC particles and the associated porosity were observed to be responsible for wide variations in the properties within the same extrudate. Attempts to reduce this variation are discussed.